Efforts of energy management have been spreading in countries of the world for the effective use of power.
As one of the efforts, there is a BEMS (Building and Energy Management System). The BEMS is a system for achieving reduction of energy consumption by performing power management of an equipment/facility and so on in a building. For example, using an art to perform supply and demand adjustment of electric power and so on, by a demand response, the reduction of the electric power and electric power amount of a building is enabled.
As the efforts of energy management in a railway system, there is an effective use of regenerative power using an energy storage device. It is common to use the regenerative power as a power for another train performing power running, but when no train performing power running is present, the power loss due to regenerative invalidation has been generated. As its countermeasure, there is a method in which an energy storage device is installed in a substation, to store regenerative power, and to utilize the power at the time of power running of a train or emergency, for example (Japanese Patent Application Publication No. 2009-67206, for example).
In the case of storing regenerative power in an energy storage device, since regenerative power is generated in a large power/power amount at one time, and is fragmentarily generated, an energy storage device with a limited capacity becomes impossible to effectively use the power, if the power is not systematically charged/discharged. Accordingly, a system to create a charging/discharging plan of an energy storage device to store regenerative power becomes necessary.
In addition, a ratio of a remaining charge power amount to a battery capacity of an energy storage device at the time of full charge is called State of Charge: Charging State (hereinafter, referred to as an SOC). There is a proper range of the SOC for preventing performance deterioration of an energy storage device depending on the kind of the energy storage device, and charging/discharging control of the energy storage device is performed within the proper range. In addition, in the following description, a proper range of an SOC of an energy storage device shall be called an SOC width.
In addition, as described above, in the conventional art, the systematic charging/discharging in an energy storage device has been performed within a SOC width. However, it does not greatly affect the performance deterioration of the energy storage device to temporarily exceed the SOC width. For the reason, there was a case in which the regenerative power cannot be effectively utilized in the conventional art.